Polycarbonate resin has excellent toughness, impact resistance, thermal stability, self-extinguishing property, dimensional stability, and heat resistance. Accordingly, polycarbonate resins have been widely used in a variety of products, such as electric and electronic products and automobile parts, and as a substitute for glass, for example in lens. However, when polycarbonate resins are used in a product requiring transparency, the polycarbonate product can have reduced scratch resistance as compared to a glass product and further the product can yellow over time when exposed to sunlight.
Polymethylmethacrylate (PMMA) resin has excellent weather resistance, transparency, adherence and strength such as flexural strength and flexural strain differing from polycarbonate resin. PMMA resin has accordingly been used in various applications such as adhesives, lighting materials, and building materials. However, PMMA has inferior impact strength, so it may not be useful for reduced thickness products requiring impact strength.
When polycarbonate resin is alloyed with PMMA resin, the alloy is expected to have both excellent impact resistance and excellent scratch resistance. However, compatibility of the two resins is low and the difference between their refractive indices is large. Accordingly, the resultant products are generally opaque, can have a poor quality appearance, and can have deteriorated impact resistance and scratch resistance.
Currently, products can be painted or coated with specialty coatings to provide a luxurious appearance such as a high gloss. These techniques, however, requires several processing steps, can increase defect rates, and can generate hazardous volatilize components, which can increase the costs.
In order to solve these problems, a material that does not requiring painting or coating has been developed. There is still a need, however, for a product which exhibits a good balance of several different properties, such as impact resistance, heat resistance, scratch resistance and the like.